The Rock Springs Field Office encompasses 5.4 million acres, 3.6 million acres of which are public lands managed for the benefit of all Americans. The Rock Springs Field Office also manages 3.5 million acres of federal subsurface mineral estate located in southwestern Wyoming. The remaining lands are either privately owned, or managed by other federal or state agencies. The area includes portions of five counties; Sweetwater (5 million public surface and/or mineral acres), Sublette (1.65 million public acres), Fremont (2.4 million public acres), Lincoln (1.1 million public acres), and Uinta (0.5 million public acres).
A variety of ecosystems can be found, including dry, high-altitude deserts and lush, forested mountains. Elevation ranges from about 6000 to 9500 feet. While winter can be long and cold, the summer is delightful with very comfortable temperatures. Low humidity makes both winter cold and summer heat tolerable. Precipitation is low, averaging between 7 to 9 inches in the lower elevations but it increases at higher elevations.
There are several rivers with the Green River being the most prominent as it serves as the upper source for water in the Colorado River system. Two dams have been built on the Green River including Flaming Gorge (actually located in the State of Utah) and Fontenelle which store and regulate water flows for downstream users. Other major perennial rivers (flows year round) include the Big Sandy, Black's Fork's, Sweetwater, and Henry's Fork.
Since southwest Wyoming is rural, wildlife is abundant. Over 350 species can be found including big game species (elk, mule deer, moose, and antelope), raptors (eagles, hawks, and owls), other birds (waterfowl, songbirds, and grouse), small mammals (rabbits, fox, and coyotes), and fish (trout, salmon, and whitefish) are just a few examples. In addition to wildlife, the Rock Springs Field Office area provides habitat to support herds of wild horses.
This part of Wyoming has been inhabited by humans for at least 12,000 years. With the advent of EuroAmerican settlement of the western US, several historic trail systems can be found including Oregon, California, Mormon, and Pony Express Trail. This particular trail system was used by 400,000 people between the years of 1843 and 1869.
The Rock Springs Field Office area is brimming with outdoor recreation opportunities. Fishing, hunting, hiking, camping, horseback riding, river-rafting, cross-country skiing, mountain biking, snowmobiling, sight-seeing, and visiting historic places are some of the fun things to do here.
Population centers include the communities of Rock Springs, Green River, Wamsutter, Eden-Farson, Superior, Wamsutter, Baroil, and Granger. Major industries found include mining of coal and trona (sodium), oil and natural gas production and processing, electrical power generation, agriculture/livestock grazing, and service-providing businesses. Rock Springs has the largest population with approximately 20,000 people, next is the City of Green River with 13,000. The smallest town is Granger with a population of 126.